泛酸钙对全饥饿鼠存活时间、尿氮排出与学习记忆影响的实验研究

目的 :了解泛酸钙对全饥饿鼠的存活时间、尿氮 (N)排出及脑功能的影响 ,为提高饥饿动物的生存适应能力提供实验依据。方法 :以饥饿大小鼠为模型 ,泛酸钙分成高 (2 5 0mg·kg 1·d 1)、中 (12 5mg·kg 1·d 1)、低 (2 5mg·kg 1·d 1) 3个剂量组 ,灌胃补充。观察大、小鼠饥饿后的存活时间、体重变化、大鼠的尿N排出及饥饿前后小鼠的学习与记忆功能。结果 :泛酸钙能够延长饥饿大、小鼠的存活时间 ,其中中剂量组小鼠的存活时间从 (4.4± 1.0 )d延长到 (5 .6± 1.0 )d ,(P <0 .0 5 ) ;大鼠从 (9.6± 0 .9)d延长到 (10 .6± 0 .9)d ,(P <0 .0 5 ) ;中剂量组大鼠蛋白质保存期明显长于全饥饿对照组 ,中高剂量泛酸钙能显著提高饥饿第 3天小鼠的记忆能力 ,电击次数明显降低 ,分别为 2 .0 0± 0 .76和 2 .14± 1.0 7(对照组为 2 .70± 1.34)。结论 :泛酸钙能延长饥饿鼠的存活时间及蛋白质保存期 ,提高小鼠的记忆功能 ,对饥饿鼠有一定的保护作用     

硫酸镍对小鼠脑组织钙调素、ATP酶活性的影响

为探讨镍化合物对中枢神经系统毒作用及其机理,用小鼠腹腔注射(ip)硫酸镍染毒,检测小鼠自发活动和协调运动;并于0～4℃条件下制备脑匀浆,梯度分离酶蛋白,用比色法检测脑组织中Na+·K+-ATPase、Ca2+-ATPase活性及钙调素(CaM)含量.结果表明ip染毒后小鼠脑匀浆中Na+·K+-ATPase、Ca2+-ATPase活性及钙调素含量明显降低.提示镍可通过血脑屏障,抑制能量供给、信息传递,导致外周运动神经瘫软,小鼠活动次数降低,伏着力下降,运动失调.     

氯丙嗪和异搏定对镉致大鼠肝肾毒性的影响

目的　研究氯丙嗪和异搏定对镉致大鼠肝肾毒性的影响 ,重点观察Na+ - K+ -ATPase和Ca2 + -ATPase活性的改变。方法　大鼠按体重随机分成 4组 ,第 1组为对照组 ,皮下注射 0 . 9%氯化钠 ;第 2组为单纯染镉组 ,皮下注射7μmol/kg的氯化镉溶液 ;第 3、 4组分别腹腔注射氯丙嗪 5mg/kg (CPZ干预组 )或异搏定 4mg/kg (Ver干预组 ) ,1h后皮下注射 7μmol/kg的氯化镉。各组处理 6周后 ,测定尿乳酸脱氢酶 (LDH)、尿蛋白、尿镉以及肝肾组织中镉、Na+ - K+ - ATPase和Ca2 + ATPase的活性。结果　单纯染镉组与对照组比较 ,尿LDH、尿蛋白和尿镉含量明显升高 ;肝肾组织中Na+ - K+ - ATPase和Ca2 +- ATPase活性和镉含量也明显升高 ,统计学差异非常显著 (P <0 . 0 1) ;CPZ干预组与单纯染镉组比较 ,尿LDH、尿蛋白和尿镉含量及肝肾组织中Ca2 + ATPase活性明显下降 (P <0. 0 5 ,P <0 .0 1) ;Ver干预组尿蛋白、尿镉和肝肾组织中的Na+ - K+ -ATPase和Ca2 + ATPase活性明显低于单纯染镉组 ,统计学差异显著 (P <0. 0 5 ,P <0. 0 1) ,肝、肾、尿中镉含量均明显降低 ,说明Ver可抑制镉的吸收。结论　氯丙嗪和异搏定均对镉毒性有不同程度的拮抗作用。     

铅暴露对大鼠心脏功能的影响及槲皮素保护作用的研究

目的探讨铅暴露对大鼠心脏功能的影响及槲皮素的保护作用。方法成年雄性SD大鼠30只,随机分为对照组、醋酸铅组(1 g/L)和醋酸铅(1 g/L)加槲皮素(30 mg/kg)组,每组10只,通过饮水方式染毒8周。应用试剂盒检测心脏组织中超氧化物歧化酶(SOD)、丙二醛(MDA)、钠钾ATP酶(Na+-K+-ATPase)、钙镁ATP酶(Ca2+-Mg2+-ATPase)、乳酸脱氢酶(LDH)、肌酸激酶(CK)的水平变化,并进行心电图和病理形态学检查。结果铅染毒组大鼠心脏组织中MDA、Ca2+-Mg2+-ATPase水平和CK、LDH活力较对照组显著升高,而SOD和Na+-K+-ATPase水平显著下降;槲皮素组MDA、Ca2+-Mg2+-ATPase水平和CK、LDH活力较铅染毒组均显著下降,而SOD和Na+-K+-ATPase水平显著上升,心电图检查显示铅染毒组大鼠心率(HP)对照组显著下降,而P-R间期、Q-T间期较铅染毒组显著升高;槲皮素组心率较染毒组显著上升,P-R间期、Q-T间期较铅染毒组显著下降。病理学检查结果显示铅染毒组大鼠心肌组织内可见较多量炎细胞浸润,而槲皮素组有显著缓解。结论铅暴露可以导致实验大鼠心脏功能紊乱,而槲皮素对其有一定的保护作用。     

泛酸钙对全饥饿大鼠脑组织脂质过氧化的影响

目的：探讨泛酸钙对全饥饿大鼠脑脂质过氧化产物（MDA），还原型谷胱甘肽（GSH），谷胱甘肽过氧化物酶（GSH－Px)，超氧化歧化酶（SOD）的影响及可能的脑保护机制，方法：以饥饿SD大鼠为模型，灌胃补充泛酸钙，观察大鼠饥饿后不同时期脑MDA，GSH，GSH－Px及SOD的变化。结果：饥饿后大鼠脑MDA含量明显升高，泛酸钙补充后大鼠脑MDA量在禁食4与7天较饥饿前无明显升,高，与全饥饿对照组比较差异显，泛酸钙对饥饿大鼠脑SOD，GSH－Px活力无影响，但显提高GSH水平。结论：泛酸钙能抑制饥饿大鼠脑的脂质过氧化损伤，其部分作用可能是通过提高GSH水平来实现的。     

大豆硒蛋白对糖尿病大鼠心肌损伤的保护作用

目的探讨大豆硒蛋白对糖尿病大鼠心肌损伤的保护作用。方法 Wistar大鼠50只,,随机分为正常对照组(NC)、糖尿病对照组(DM)、低剂量Se治疗组(L-Se)、中剂量Se治疗组(M-Se)、高剂量Se治疗组(H-Se)。后4组腹腔注射链脲佐菌素55 mg/kg制备DM模型。第7w起,NC、DM组予0.5%CMC-Na 10ml/(kg.d),L-Se、M-Se、H-Se组分别予大豆硒蛋白2,4,8g/(kg.d)灌胃。第12w末处死大鼠,检测血糖、血清及心肌组织中SOD、GSH-Px、NOS活性和MDA、NO含量以及心肌组织中Na+-K+-ATPase、Ca2+-ATPase活性。结果与模型组比较,补充外源性大豆硒蛋白后,M-Se、H-Se组可明显降低糖尿病大鼠血糖及MDA含量(均P<0.001),显著增加血清GSH-Px、NOS活性(P<0.001),同时使心肌线粒GSH-Px活性、NO含量明显增加(均P<0.001),并且使心肌组织Na+-K+-ATPase、Ca2+-ATPase活性显著增加(P<0.01,P<0.001)。结论大豆硒蛋白对糖尿病大鼠心肌损伤具有保护作用。     

锰对神经元细胞内钙稳态影响的研究

目的研究锰对神经细胞内钙稳态的影响,重点观察神经元细胞钙离子浓度、Na+-K+-ATPase和Ca2+-ATPase活性的改变。方法选用原代培养神经元为模型,待细胞生长至最佳状态时,予以分组处理:锰处理组为含不同浓度氯化锰(0,25,100,400μmol/L)的培养液,培养神经细胞12h后,通过倒置相差显微镜观察细胞形态的改变,并检测神经元细胞内钙离子浓度、Na+-K+-ATPase和Ca2+-ATPase活性的变化。结果随着染Mn剂量的加大,神经元形态出现异常,细胞内钙离子浓度逐渐升高;细胞Na+-K+-ATPase和Ca2+-ATPase活性也逐渐下降。结论锰通过影响与维持钙稳态相关的酶(Na+-K+-ATPase和Ca2+-ATPase)活性,干扰神经元细胞内钙稳态,进而造成神经元细胞损伤。     

泛酸钙对全饥饿大鼠血清酮体、游离脂肪酸的影响

目的探讨泛酸钙对全饥饿大鼠可利用能源物质酮体(KB)和游离脂肪酸(FFA)的影响及可能的保护作用,为研制延长饥饿耐受时间的营养剂提供科学依据.方法以饥饿SD大鼠为模型,灌胃补充泛酸钙,观察饥饿后不同时期血清酮体和游离脂肪酸的变化.结果血清KB和FFA水平在饥饿后逐渐升高,分别于禁食4 d和2 d达到峰值(2.67±0.30)mg@100 ml-1和(793.75±99.85)μmol@L-1,之后开始下降.泛酸钙补充后FFA峰值显著降低(655.92±135.12)μmol@L-1,禁食9 d的KB(0.48±0.08)mg@100 ml-1和FFA(290.46±96.49)μmol@L-1水平显著高于全饥饿对照组的(0.40±0.07)mg@100 ml-1和(167.43±46.78)μmol@L-1,(P＜0.05,＜0.01).结论泛酸钙能延缓饥饿动物能源物质的消耗,可能对饥饿动物有一定的保护作用.     

地卓西平对甲基汞致大鼠脑皮质细胞内钙稳态失调的影响

目的研究地卓西平对甲基汞致大鼠脑皮质细胞内钙稳态失调的影响。方法 Wistar大鼠32只,按体重随机分成4组,每组8只。第1组为对照组,腹腔注射0.9%氯化钠;第2组为低剂量甲基汞染毒组,腹腔注射4μmol/kg的甲基汞溶液;第3组为高剂量甲基汞染毒组,腹腔注射12μmol/kg的甲基汞溶液;第4组为地卓西平预处理组,隔日皮下注射0.3μmol/kg地卓西平,2 h后腹腔注射12μmol/kg的甲基汞溶液;注射容量均为5 ml/kg,染毒4周,每周5次。观察神经细胞内Ca2＋浓度及其凋亡情况,同时测定脑皮质Hg含量和与维持钙稳态相关的酶Na＋-K＋-ATPase和Ca2＋-ATPase活性。结果染毒4周后,随着染毒剂量的增加,脑皮质Hg含量和细胞内Ca2＋浓度均明显升高（P〈0.01）;细胞凋亡率明显高于对照组（P〈0.01）;脑皮质Na＋-K＋-ATPase和Ca2＋-ATPase活性均不同程度的受到抑制。地卓西平预处理可以明显缓解神经细胞凋亡和细胞内Ca2＋超载,对Na＋-K＋-ATPase和Ca2＋-ATPase活性也有一定程度的恢复作用。结论甲基汞通过抑制与维持钙稳态相关的酶Na＋-K＋-ATPase和Ca2＋-ATPase活性,干扰神经细胞内钙稳态,进而造成神经细胞凋亡。地卓西平可以阻断Ca2＋通道对钙稳态失调引起的细胞损伤有拮抗作用。     

三甲基氯化锡染毒对大鼠肠道推进功能的影响

将24只SD大鼠分为4组,三甲基氯化锡(TMT)组分别给予4.64 mg/kg、10 mg/kg和21.5 mg/kg TMT染毒,对照组给予生理盐水,染毒后24 h测定肠道推进功能和Na+-K+-ATPase活力;另将24只大鼠分为4组,TMT组给予10mg/kg染毒,对照组给予生理盐水,分别在3 d和6 d测定肠道推进功能和Na+-K+-ATPase活力。结果显示,大鼠小肠不同部位的Na+-K+-ATPase活力不同。经TMT染毒后肠道推进率较对照组明显降低(P0.01),中高剂量染毒组的肠道Na+-K+-ATPase活力明显降低(P0.01)。10 mg/kg TMT染毒大鼠3 d和6 d肠道Na+-K+-ATPase活力亦明显下降(P0.05)。提示TMT染毒可能会抑制小肠推进功能,推进率的下降可能与肠道Na+-K+-ATPase活力抑制有关。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.